Southern Pacific EMD SW8 1111 at San Diego, California, April 10, 1980. Photographer: Peter Arnold.

(Craig Garver, Public domain,


GM-EMD logo blue and white


The EMD SW8 is a diesel switcher locomotive manufactured by General Motors Electro-Motive Division and General Motors Diesel between September 1950 and February 1954. Power is supplied by an EMD 567B 8-cylinder engine, for a total of 800 hp (600 kW). A total of 309 of this model were built for United States railroads and 65 for Canadian railroads. Starting in October 1953 a number of SW8s were built with either the 567BC or 567C engine.


US Army SW8s

The United States Army ordered 41 SW8s, numbered 2000–2040, for service in Korea during the Korean War. These were shipped in the spring of 1951.

After the Korean War, many US Army-owned SW8s were turned over to the South Korean government while others were retained by the Army and assigned to various Army posts, depots and ammunition plants. Most were retired around 1990 and replaced in service by rebuilt geeps, such as GP10s from VMV in Paducah, KY, and other rebuilders.

Of all of the locomotives turned over to the Korean National Railroad, only one, KNR No. 2001, believed to be ex-USAX No. 2011, still exists. As of May 2011 it was stored in the back of a locomotive shed in the Korea Railroad Busan Rolling Stock Workshop, 125 Sincheon-ro, Busanjin-gu, Busan, Korea 614–765. Diesel Locomotive Team Leader Kim Hyun-Sik stated KORAIL is in talks with the city of Pusan to put the locomotive on display in the city as a part of Korea's heritage, as it is the oldest diesel locomotive in the country.

Two examples of these locomotives, ex-USAX No. 2019 and No. 2022, are preserved at the Heart of Dixie Railroad Museum in Alabama. After serving in Korea, No. 2019 was sent back to the manufacturer for reconditioning in 1953.No. 2022 was rebuilt in 1955. Both served in military bases in the United States until the early 1990s, finishing their careers at Fort Campbell, Ky. The Heart of Dixie Railroad Museum acquired them in 1995.


EMD SW8 switching locomotive, manufactured 1951. Retired from the United States Air Force Titan missile program,

this locomotive is now on display at the Air Force Space & Missile Museum, Cape Canaveral Air Force Station, FL.

(Fl295 at English Wikipedia, Public domain, via Wikimedia Commons)


Other models

In addition, 12 TR6 cow-calf paired sets were produced.

In May 1953, a single example of the SW8 was built with a hydraulic transmission as model DH2. This locomotive was displayed at a trade show in 1955, but no sales of the DH2 followed. The locomotive was rebuilt with a standard electrical transmission, and served EMD as plant switcher No. 105 until 1968.

The first TR6A, Southern Pacific 4600, later numbered 1100, is preserved at the Western Pacific Railroad Museum at Portola, California.


Original buyers

SW8 Locomotives built by Electro-Motive Division, USA

Railroad Quantity Road numbers Notes
Electro-Motive Division (plant) 1 105 Built as model DH-2
Electro-Motive Division (demonstrator) 1 800 to Illinois Terminal Railroad 725
Electro-Motive Division (demonstrator) 1 801 to Georgia Northern Railway 801
Electro-Motive Division (demonstrator) 1 500 to Cuyahoga Valley Railway 855
Aliquippa and Southern Railroad 3 800–802 Built with 567BC engines
Atlantic Coast Line Railroad 10 50–59
Bamberger Railroad 2 601–602
Boston and Maine Railroad 8 800–807
Canton Railroad 4 40–43 42-43 were built with 567C engines
Cedar Rapids and Iowa City Railway ("Crandic") 3 91–93 Built with 567BC engines
Chicago and North Western Railway 1 801
Chicago, St. Paul, Minneapolis and Omaha Railway ("Omaha Road") 4 126–129
Chicago, Rock Island and Pacific Railroad 28 811–838 836-838 were built with 567BC engines. 838 was acquired by Pfizer Incorporated in 1989 and then donated to the Danbury Railway Museum in 2002.
Chicago, West Pullman and Southern Railroad 5 42–46
Cincinnati Union Terminal 8 30–37
Colorado and Wyoming Railway 12 201–212
Columbia Iron and Steel 1 1
Delaware, Lackawanna and Western Railroad 11 501–511
De Queen and Eastern Railroad 1 D-3
Detroit, Toledo and Ironton Railroad 2 900–901
Donora Southern Raileoad 10 802–811
Great Northern Railway 3 98–99, 101 98–99 to Burlington Northern. 101 was rebuilt from an NW1
Lake Terminal Railroad 4 821–824
Lakeside and Marblehead Railroad 2 13–14
Lehigh Valley Railroad 29 128–129, 250–276 256-273 built with dynamic brakes.
Louisiana and North West Railroad 2 40–41
Ludington and Northern Railroad 1 16
Merchants Despatch Transportation 1 15
Monessen Southwestern Railway 2 22, 26
New Orleans Union Passenger Terminal 3 1–3 Built with 567BC engines
New York Central Railroad 26 9602–9627 To Penn Central then Conrail 8602–8627, 8618 is preserved on the Strasburg Railroad
New York Central Railroad (Chicago River and Indiana Railroad) 2 9600–9601 To Penn Central then Conrail 8600-8601
New York, Chicago and St. Louis Railroad ("Nickel Plate Road") 8 107–114
North Louisiana and Gulf Railroad 2 37–38 Built with 567BC engines
Pittsburgh Coke and Chemical Company 1 4
Poplar Ridge Coal 1 801
Reserve Mining Company 2 1200–1201
Roscoe, Snyder and Pacific Railway 1 200
South Shore Railway 1 12 to Illinois Central Railroad 802
Southern Pacific Company 20 4604–4623 All built with dynamic brakes; 4622-4623 built with 567BC engines
Southern Pacific (Texas and New Orleans Railroad) 5 12–16
Steelton and Highspire Railroad 1 26
Tennessee Coal, Iron and Railroad Company 6 750–754, 770
Texas and Pacific Railway 8 811–818
Tremont and Gulf Railway 2 75, 77 to Illinois Central Railroad 800 and 801
Unity Railways 1 53
United States Army 41 2000–2040 All 41 served in the Korean War, including the 2019 and 2022 now at the Heart of Dixie Railroad Museum. 2002 is on display at the National Museum of Transportation in Kirkwood, Missouri.
United States Steel 1 109
Wabash Railroad 9 120–121, 125–126, 128–132
Wheeling Steel 2 1152–1153
Wichita Falls and Southern Railroad 2 801–802 to Rock Island 839–840
Woodward Iron Company 2 60–61
Total 309

Locomotives built by General Motors Diesel, Canada

Railroad Quantity Road numbers Notes
Algoma Central Railway 2 140–141
Algoma Steel 1 50
Canada and Gulf Terminal Railway 1 356
Canadian National Railways 34 8500–8533
Canadian Pacific Railway 10 6700–6709
Dominion Foundries and Steel Company ("Dofasco") 2 11–12
Dominion Iron and Steel 2 11–12
Essex Terminal Railway 2 102, 104 Essex Terminal 104 last SW8 built 2/54
Steel Company of Canada 7 71–77
Wabash Railroad 4 122–124, 127 Bought for use in Canada
Total 65


Railroad Quantity A units Quantity B units Road numbers A units Road numbers B units Notes
Electro-Motive Division (demonstrator) 1 1 1600 1600B to Southern Pacific 4600 (A), 4700 (B)
Oliver Iron Mining Company 8 8 1207A–1213A, 1216A 1207B–1213B, 1216B
Southern Pacific Company 3 3 4601–4603 4701–4703
Total 12 12


Type and origin
Power type: Diesel-electric
Builders: General Motors Electro-Motive Division; General Motors Diesel (GMD, Canada)
Models: SW8, TR6
Build dates: September 1950 – February 1954
Total produced EMD SW8: 309
Total produced GMD SW8: 65
Total produced EMD TR6A: 12
Total produced EMD TR6B: 12
​• AAR B-B
• UIC Bo’Bo’
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Length: 44 ft 5 in (13.54 m)
Width: 9 ft 11.6 in (3.038 m)
Height: 14 ft 6.2 in (4.425 m)
Locomotive weight: 230,000 lb (104,326 kg)
Prime mover: EMD 8-567B
Engine type: V8 Two-stroke diesel
Aspiration: Roots-type supercharger
Cylinders: 8
Performance figures
Maximum speed: 65 mph (105 km/h)
Power output: 800 hp (600 kW)
Tractive effort - Starting: 57,000 lbf (254 kN) at 25%
Tractive effort - Continuous: 36,000 lbf (160 kN) at 11 mph (18 km/h)
Locale: North America, South Korea